Well, I did use the words “mix green”. But what I really mean and should have been more careful to always say is “cross through more or less colorful greens when drawing a direct line between sRGB yellow and blue on an LCh or JCh (of various flavors) color wheel”.
Minimally, the various cams are an attempt to capture how we perceive colors, including, I hope - someone please correct me if I’m wrong - how we conceive colors as progressing from one color to the next.
Do we expect a perceptually uniform visual (not talking about mixing actual paints) progression from sRGB yellow to sRGB blue to cross into greens? I can believe “Maybe, but the greens will be very unsaturated”. But I can’t believe “Yes, and the greens will be bright and cheerful”.
I also can’t believe “No, instead the colors cross over oranges and magentas” as seems to be the case with plotting these colors on the LCh color wheel. My conception of “how colors progress” would require a more orange shade of yellow than sRGB yellow, to get oranges and magentas in a progression from yellow to sRGB blue.
Here’s a plot of xicclu JCh (to the left, crossing almost through gray) and xicclu LCh crossing the positive a-axis through orange-yellow) to show what I mean by drawing lines on a color wheel and having the traversed colors look like a believable progression. Please keep in mind I created the progression rather quickly using a spreadsheet, xicclu, and GIMP, so there’s plenty of room for error on my part:
Well, according to that nice “Golden” paint website that @Claes and @paperdigits linked to, sRGB blue isn’t a paint they can mix, and neither is sRGB yellow, though I’m fairly sure sRGB yellow is an actual surface color that paint pigments can produce. But I think sRGB blue isn’t an actual surface color at all.
My understanding of how real world paint pigments mix - multiplying spectral reflectance curves and such - is minimal, practically non-existent. Hopefully other people in this thread might be qualified to predict what might happen when mathematically mixing imaginary paint pigments.